JOIN TWO TABLES IN IMPROMPTU

I've got one question.
I have two same or similar tables (they have the same structure, but data are different). I would like to join all records from these tables into one table. Is it possible to do that in Impromptu? If yes how could I do that?

If I do what you told me, I woudn't need to use hotfile.
It could be done without hotfile, but the items would be duplicated in the table.
My problem is to have items once in a table and all records in the table (records from second table under records from first table).

I don't think what you want can be done in Impromptu. What you realy want is
to make a third tabel that contains all the records of the first and the
second without the duplicate rows. Impromptu isn't capable of this. It will
always see the two tables as physically different and not as one.
The best way for you to solve the problem, is find a way to make it happen
in you database. Then add the created component to the Catalog.

I agree with the post below, do it at the database level. Depending how often these tables change you could either create a view (if they change frequently), or create a table using the select union all statement (if they hardly ever change). Another option, if you are using Oracle (probably similar things in other databases) is a materialized view which could be refreshed at some regular interval.
We use views a lot and Impromptu treats them just like another table, so you don't lose your formatting, summaries, security, etc.